From a GUI perspective: From Applications>Ubuntu Software Center, I installed 'alien' (package converter, not video game!) and then I installed the suggested front-end GUI Package Converter .deb software from code.google.com/p/foxoman. The 'Package Converter' item then appeared under Appplications>System Tools. I ran it, converted my .RPM to .deb and installed the resulting Debian package. A beautiful experience. Thanks!
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John KAug 13 '10 at 2:40

Ubuntu is Debian based and therefore uses.deb packages to install. If you want to install .rpm packages, you first should convert them into .deb packages with a conversion software such as alien. Then you can use gdebi or dpkg to install them.

However, caution must be applied by doing that. Even such conversion software does not always create the correct dependencies to other packages. Therefore, the software installer might refuse to install your package because of missing dependencies, or the software might not work very well because not all dependencies have been created and maybe some libraries are missing.